Form

110

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3000

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Art.

No.

536

001.

02B

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SCHMIDT ® Flow Sensor SS 20.600

The powerful industrial professional for demanding applications invol-ving air and gases.

Industrial processes

Pneumatic technology

Simply a question ofbetter measurement

Evaluation electronics

Output signals: - 4 ... 20 mA / 0 ... 10 V- Impulses (0 ... 100 Hz or impulse / m3)

Flow rate volumes of gases – an important parameter in industrial processes

Measures to save energy and to assure quality in the production process are of particular importance in industrial processes. The ability to measure volumetric flow rates and volumetric flow of gases precisely has an important role to play in this. The require-ments imposed on the flow rate sensor used for this are demand-ing: the sensor has to be capable of delivering precise measuring results for different gases, at high overpressures and across wide ranges of temperature. It also has to be able to do so under the most difficult environmental conditions such as explosive areas and in the open air. A further criterion involved in the selection of a suitable sensor is the prevention of maintenance and its attendant high secondary costs. Ease of assembly and reliable measuring values for many years: that is the objective.

The “true professional“ for industrial processesand pneumatic technology

The thermal SCHMIDT ® Flow Sensor SS 20.600 is the perfect solution for demanding industrial applications. It can be used for a diverse range of applications, such as compressed air monitoring, gas monitoring on process burners, consumption recording of gases and a great deal more. The sensor records flow speed as well as me-dia temperatures of up to 120 °C. It can be used in small tubes from DN 25 upwards and can involve a sensor length of up to 1 metre to measure the volumetric flow rate in large channels and ducts. If the standard version is not sufficient for overpressure of up to 16 bar, a version rated for up to 40 bar can be selected.

This sensor is very easy to install: screw down the sensor using the compression fitting included, align the sensor in the gas flow and centrally in the pipe, connect up its electrical wiring – and job done!

This sensor operates without any moving parts and employs a meas-uring principle that eliminates any drift or signs of ageing. This re-duces the maintenance required for the sensor – depending on how contaminated the medium becomes – to the occasional need for the sensor head to be blown through (air blast) or rinsed in water.

High gas speeds, special gases or explosion protec-tion? The SS 20.600 can do (almost) everything!

The special chamber head sensor records flow speeds of 0.2 m / s up to 220 m / s. In order to obtain precise measuring results across this very broad speed range, every sensor is individually checked and compared in an elaborate pressurised wind tunnel.

To enable this sensor to be used in different gases, a range of indi-vidual versions is available, e. g. for pure oxygen, CO2, methane. Of particular interest: Hydrogen will become an important parameter in future, and it can also be measured using the SS 20.600 (option). For use in other media in potentially explosive atmospheres and environments, the sensor is optionally available in an explosion-protected version (ATEX).

Protective chain

How does it work?

The flow sensor element is protected, and is positioned in the chamber head in a way that favours unimpeded flow. Sensors for flow rate as well as temperature are arranged on the ceramic sensor element. For protection purposes, sensors are coated with a thin layer of glass. The flow sensor is heated to 40 K above the temper-ature of the medium. The power required to maintain this positive temperature differential (“overtemperature“) is an indicator for the flow rate speed that the sensor issues as “normal speed“ (linear current / voltage / impulse signal). This is a great advantage of the measuring principle: No additional measurement of the pressure or temperature of the medium is required.

Practical examples

Branch Application The solution with SS 20.600

Industrial processes Measurement of incoming air to control industrial burners /incinerators

- High flow rate speeds of up to 220 m / s- Measurement of standard volumetric flow rate independent of pressure and temperature - O2 version for pure oxygen

Recording of inert gas volumes (nitrogen) - Specific versions for gas and gas mixtures- Resistant to overpressure up to 40 bar

Control of combustion gas volume (natural gas, methane, ...) - ATEX version- For pipe diameters from DN 25

Detection of gas consumption - Acquisition of the flow rates of “almost zero“ to the maximum value (detection gas slippage)- From - 40 °C temperature of medium usable (ATEX version)

Pneumatic technology Compressed air consumption, compressor control - Extremely wide measuring ranges for flow rate - Simple signal processing: impulse per m3

Leakage measurement - Measurement from 0.2 m / s- Design principle eliminates age-dependent drift

Monitoring of minimum flow rate - High-precision adjustment (1 % precision)- Very fast response speed

Protective chain

Flow sensor (incl. temperature measurement)

220 m / s

flow

flow

Individually adapted to suit every application – you have the choice!

For optimum installation in the various different pipe diameters, 4 standard sensor lengths as well as special lengths of 120 to 1,000 mm can be selected. A remote version is available for difficult installation conditions. The probe length itself and the cable length between sensor and housing can be selected.

To enable the sensor to be adapted to flow rate conditions, 6 stand-ard measuring ranges are available, extending up to 220 m / s. The volumetric flow rate is the result of the flow rate speed, multiplied by the pipe cross-sectional surface area and a profile factor. Howev-er, customer-specific measuring ranges can also be supplied in incre-ments of 0.1 m / s. The advantage of this is that a desired maximum volumetric flow rate determines the measuring range of the sensor depending on pipe diameter. Example: Maximum volumetric flow rate of 450 m³ / hr with a pipe diameter of DN 65 yields a maximum flow rate measuring range for the sensor of 48.1 m / s (= 20 mA or 10 V). For the purposes of simple conversion, the homepage fea-tures a flow rate calculator that also determines the profile factor, which is dependent on the pipe cross section.

For evaluation systems with impulse inputs, the SS 20.600 offers an additional impulse output for the flow rate signal. There is a standard measuring range of 0 … 100 Hz available or, if the pipe diameter is indicated, impulses per m³ as a customer-specific output as an option.

Measure other gas media too? Absolutely!

More often than not, the medium being measured is not air, but instead comprises other gases or gas mixtures. For these special applications, gas-specific versions of the SS 20.600 can be supplied. With these versions, the sensor has a specific correction – based on adjustment in air – programmed in. These correction factors were established individually for each gas on real gas channels. For gas mixtures, each correction is calculated on the basis of an individual customer specification. For media with an oxygen content of > 21 % of volume all components in contact with the media must be cleaned to remove greases, oils and / or other combustible elements. A spe-cific grease-free and O2 > 21 % variant provides the required safety for this application.

Accuracy – in black & white

As an option, the SS 20.600 can be supplied with a high precision adjustment for air that can also be used for pure oxygen and nitrogen. This measurement is carried out at SCHMIDT Technology. The high levels of precision and reproducibility are documented in an ISO calibrationcertificate (attached). This calibration can be renewed to suit user definitions.

Everything in view

The LED display is dual function. In “normal“ operation the 4 x LED’s illuminate steady green in sequence. In “fault“ condition reportable faults are indicated by red flashing LED’s. The instru-ment will output V and mA and change-over is automatic.

Use in combustible or explosive media

The optional ATEX version SS 20.600 Ex is designed for use in the “Zone 2“ category of explosive gas atmospheres. For this, specific protection functions are incorporated, among other things, one example being a protective sleeve for the plug connector and the ground / earth terminal on the housing or, on the remote version, with an additional one on the sensor tube. This version enables a minimum medium temperature of - 40 °C to be reached.

6

Ø ID

R

E

AL

L

36SLDA / 2

DA

SW 27 SW 24

Erdungsklemme

7,2

24Ø

G1/2

49

12

130

67,3

Ø

17 39L

15Ø

25

29

8

Flow

12.5

Ø

Ø

47L 42

88

130

67,3

SW 27 SW 24

G½

49

12

17 39L

15Ø

25

29

8

Flow

Ø

47L 42

88

16,5

58 59

36

4

44

50

2160 80

8,5

Ø 4,5

4 x

16,5

58 59

36

4

44

50

2160 80

8,5

Ø 4,5

4 x

Dimensions of the basic sensor

Remote sensor including wall mounting bracket

Mounting parametersMounting instructions

DA = Outer diameter of tube SL = Length of welding sleeve E = Adjustable length of sensor tube AL = Extended length of compact sensor R = Reference length L = Length of sensorAll dimensions in mm

infeed line 10 x ID min. outfeed line 5 x ID min.

Remote sensor, ATEX version (optional)including wall mounting bracket

ATEX version SS 20.600 Ex (optional)

76

Technical DataMeasuring data

Measuring values Standard flow velocity wN normalized to 20 °C and 1,013.25 hPa; temperature of the medium TM

Measuring fluid Air or nitrogen; optional: Methan, natural gas, biogas, CO2, oxygen and specialty gases and gas mixtures

Measuring range wN 0 ... 10 / 20 / 60 / 90 / 140 / 220 m / s; optional: customised measuring ranges in 0.1 m / s-steps

Lower detection limit wN 0.2 m / s

Measuring range TM - 20 ... +120 °C; SS 20.600 EX: - 40 ... +120 °C

Accuracy

Standard wN 1) ± 3 % of measured value + (0.4 % fmr; min. 0.08 m / s)

High precision wN (optional, for air, nitrogen, oxygen only) 1)

± 1 % of measured value + (0.4 % fmr; min. 0.08 m / s)

Repeatability wN ± 1 % of measured value

Response time t90 wN 1 s (jump from 0 to 5 m / s air)

Temperature gradient wN < 8 K / min at wN = 5 m / s

Measurement accuracy TM ± 1 K (10 ... 30 °C); ± 2 K remaining measuring range (@ wN > 5 m / s)

Operating temperature

Sensor - 20 … + 120 °C ; SS 20.600 EX: - 40 ... +120 °C

Electronics - 20 … + 70 °C

Storage temperature - 20 … + 85 °C

Material

Housing Aluminium, anodized

Sensor tube, screw connection Stainless steel 1.4571

Sensor head Platinum resistor element (glass-passivated), PPO / PA

Protective sleeve Aluminium, anodized

Sensor cable (on remote sensor) Jacket PUR, halogen-free, UL

General Data

Medium, environment Non-condensing (up to 95 % RH)

Maximum pressure 16 / 40 bar; oxygen (O2 > 21 %: 20 bar

Display 4 x Duo LEDs green / red / orange

Supply voltage 24 V DC ± 20 %

Current intake Approx. 50 mA (without impulse outputs); max. 250 mA

Analogue outputs for temperature and flow rate Auto U / I

0 … 10 V / 4 … 20 mA (protected against short circuits)Voltage output: > 550 ΩCurrent output: < 500 ΩHysteresis: 50 Ω

Impulse outputs Frequency 0 … 100 Hz, optional: 1 impulse / 1 m 3; 1 impuls e/ 0.1 m 3 / h; 1 impulse / 0.01 m 3 / hr (max. 100 Hz)1. Highside driver to supply voltage (not galvanically isolated) High level: > supply voltage - 3 V Short circuit current limitation: 100 mA 2. Semiconductor relay (galvanically isolated); max. 30 V / 50 mA

Electrical connection Plug-in connector M 12, screwed, 8-pin, male

Maximum line length Voltage signal: 15 m, current signal / impulse: 100 m

Mounting position Any (with vertical downdraft: lower limit of measuring range 2 m / s @ 16 bar)

Installation tolerance ± 3° to flow direction

Minimum tube diameter DN 25

Type / class of protection IP 65 (housing), IP 67 (sensor) / III (SELV) or PELV

ATEX category II 3G Ex nA ic IIC T4 Gc

Sensor length Compact sensor: 120 / 250 / 400 / 600 mm; special lengths from 120 to 1,000 mm

Weight Approx. 500 g max. (without connection cable)

1) under reference conditions, related to adjustment reference

7 8

Accessories

Shielded connection cable available in various lengths

LED measured value display (see seperate brochure)For visualization purposes directly on location, an LED unit is available to display measuring values.The advantages: Display in m / s or m3 / h Programmable output signal Two programmable relay outputs Power supply: 85 − 250 V AC or 24 V DC Power supply to the connected sensor Separate version with “sum“ function Detection of flow direction by the use of two SS 20.600 units arranged at 180° to one another

Welding steel sleeves Type no. 524 916 or stainless steel Type no. 524 882

Coupler socket with screw type terminals Type no. 524 929

SCHMIDT ® Probe ball valve (see seperate brochure)A choice of probe ball valves are available to facilitate fast remov-al and installation in 1” to 2” pipework. Advantage: even while the system is under pressure, it is no problem to install or remove the sensor.

A straight-run ball valve is available for larger pipework diameters.

Extended connection options with field bus modules

As an option, the following variants are available for integrating the SS 20.600 into existing BUS systems: DeviceNet ProfiBUS DP Others on request

The BUS modules are housed in a rugged auxiliary housing. The standard outputs are available in addition to the BUS signal.

Sensor 1 Sensor 2

FLOW FLOW

Order information for the SCHMIDT ® Flow Sensor SS 20.600

Description Article number

Basic sensor SCHMIDT ® Flow Sensor SS 20.600; output signal 4 ... 20 mA and 0 ... 10 V; impulse output, incl. pressure-tight stainless steel compression fitting 524 600 A B C D E F G H PP

Optionen

Mechanicaltype

Sensor length 120 mm 1

Sensor length 250 mm 2

Sensor length 400 mm 3

Sensor length 600 mm 4

Special lengths (> 120 mm to 1,000 mm): Length: _____ mm 8

Remote sensor incl. wall mounting bracket - sensor length (selectable lengths: 120 / 250 / 400 / 600 mm): _____ mm - cable length (1 ... 10 m):_____________________________________m

9

Pressure-tight compression fitting, stainless steel G ½ 1

Pressure-tight compression fitting, stainless steel R ½ (P T) 2

Measuring ranges 1 and calibration

Measuring range 0 ... 10 m / s 1

Measuring range 0 ... 20 m / s 2

Measuring range 0 ... 60 m / s 3

Measuring range 0 ... 90 m / s 4

Measuring range 0 ... 140 m / s 5

Measuring range 0 ... 220 m / s 6

Special measuring range (10 ... 220 m / s) in 0.1 m / s-steps: _____ , _____ m / s 9

Standard adjustment 1

High-precision adjustment check incl. ISO calibration certificate 2

Standard adjustment check with conversion factor for methane 2)

wN max: 90 m/s 3

Standard adjustment check with conversion factor for biogas (60 % methane, 40 % CO2) 2)

wN max: 35 m/s 4

Standard adjustment check with conversion factor for CO2 2)

wN max: 60 m/s5

Standard adjustment with correction of natural gas with 88 % CH4 7

Standard adjustment check with conversion factor for special gases and mixtures 2) 9

Impulse output Standard 100 Hz (= final value of measuring range wN) 1

1 impulse / 1 m3 for pipe diameter (round) _____ mm 2

1 impulse / 0.1 m3 for pipe diameter (round) _____ mm 3

1 impulse/ 0.01 m3 for pipe diameter (round) _____ mm 4

Additional outputs

Without communications module 1

Communications modules for Profibus, others on request 3) *

Protection type ATEX

Without ATEX design (SS 20.600) 1

ATEX design (SS 20.600 EX) 2) 2

Protection type, grease-free; O2

Standard application 1

Grease-free and for O2 > 21 % 2) 3) (pmax = 20 bar) 2

Overpressure Operating pressure DD: 00 (atmospheric) ... 16 bar 00 ... 16

Operating pressure DD: 17 ... 40 2) 17 ... 40

* On request1) To select the appropriate measurement range please use our flow calculator tool on www.schmidttechnology.de 2) Not available in combination with the option ”special lengths“3) Not available in combination with ATEX

Describtion Article number

Accessories Connecting cable, 8 pole, length 5 m, with coupler socket and open cable end 524 921

Connecting cable, 8 pole, length selectable, with cable end sleeves, free of halogen 524 942

Coupler socket, 8 pole, with screw terminals, for cable ø 6 ... 8 mm 524 929

Welding sleeve steel G ½ acc. to EN 10241, 5 pieces 524 916

Welding sleeve stainless steel 1.4571 G ½ acc. to EN 10241, 2 pieces 524 882

Power supply: output 24 V DC / 1A; input 115 / 230 V AC 535 282

SCHMIDT ® LED display MD 10.010; in wall housing to to show the volume flow and flow velocity, 85 … 250 V AC and sensor supply

527 320

SCHMIDT ® LED display MD 10.010; similar to 527 320, but with 24 V DC voltage supply 528 240

SCHMIDT ® LED display MD 10.015; in wall-mounted housing, similar to 527 320 but with additional sum function and second measuring input 527 330

SCHMIDT ® LED display MD 10.015; similar to 527 330, but with 24 V DC voltage supply 528 250

Assembly kit for pipe assembly, suitable for MD 10.010 / 10.015, including pipe clamps and collar for adjustment to the pipe diameter 531 394

Probe ball valve 1“ inside thread, connection to flow sensor: ½“ inside thread incl. plug and chain 530 940

Probe ball valve 1¼“ inside thread, connection to flow sensor: ½“ inside thread incl. plug and chain 530 941

Probe ball valve 1½“ inside thread, connection to flow sensor: ½“ inside thread incl. plug and chain 530 942

Probe ball valve 2“ inside thread, connection to flow sensor: ½“ inside thread incl. plug and chain 530 943

Straight-run probe ball valve ¾“ inside thread, with threaded adapter for ½“ full-length screw connection ¾“ 532 355

Welded socket, steel, outside thread ¾“, 5 pieces 531 200

Welded socket, stainless steel, outside thread ¾“, 2 pieces 531 201

Order information SCHMIDT ® Flow Sensor SS 20.600

Form

110

0/08

/12/

3000

/2 ·

Art.

No.

536

001.

02B

· Dat

a su

bjec

t to

chan

ge

SCHMIDT Technology GmbH

Feldbergstraße 1 78112 St. Georgen / Germany

Phone +49 77 24 / 89 90 Fax +49 24 / 89 91 01

sensors@schmidttechnology.de www.schmidttechnology.de www.schmidt-sensors.com